| 摘要 |
PROBLEM TO BE SOLVED: To obtain the subject composition that is improved in shape retention on burning and its flame dripping properties by formulating a flame retarded and its auxiliary agent to a specific polypropylene composition and specifying its melt flow rate. SOLUTION: (i) 0.01-5 pts. wt. of polyethylene polymer or copolymer containing >=50wt.% of ethylene polymer units another olefin, having an intrinsic viscosity [ηE] of 15-100dl/g (at 135 deg.C in tetralin) is combined with (ii) 100 pts.wt. of a polypropylene homopolymer or copolymer of >=50wt.% of propylene polymer units with an ethylene block to prepare (A) a polypropylene composition with a melt flow rate(MFR) of 0.1-50g/10min (at 230 deg.C; 21.18N), a melting point (Tm) of 150-167 deg.C, a density of 0.895-0.910g/cm<3> , a melt tension of 1-20cN at 230 deg.C. (A) This resultant polypropylene composition is mixed with 4-50 pts.wt. of a flame retarder of 50-80wt.% halogen content and (C) an auciliary agent for flame retardation to give the objective composition with MFR of 0.1-50g/10min at 230 deg.C and 21.18N. |
